For patients with respiratory disease the symptom of breathlessness (dyspnea) is the most frequent reason for seeking medical attention. Current methods for measuring the impact of breathlessness on activities of daily living rely on face-to-face interviews conducted by health care providers. Two common measures are the Baseline Dyspnea Index representing the severity of dyspnea at a single point in time, and the Transition Dyspnea Index representing changes in dyspnea compared with the baseline level before treatment. Despite widespread acceptance of these measures, the interview technique has been criticized on three counts: (1) selection of severity of breathlessness is made by the interviewer, not the patient, and thereby can increase measurement error (2) the method cannot be applied consistently in different medical centers because the same interviewers are not employed at all test sites (3) the process is expensive due to the cost of training and employing health care providers to conduct interviews and enter data into the computer. There is a need for a less expensive, standardized approach to the measurement of dyspnea that could be applied consistently throughout the world. In Phase I of this project computerized versions of the Baseline Dyspnea Index and the Transitional Dyspnea Index were developed and tested for concurrent validity by comparison with interview versions, and for construct validity by comparison with pulmonary function tests. The aims of Phase II are to determine further psychometric and clinical properties of the standardized methods: test- retest reliability of both the Baseline and Transition Dyspnea Indices, responsiveness and the minimally important clinical difference of the Transition Dyspnea Index. Subjects employing the new, standardized computer methods will be 126 patients diagnosed with chronic lung disease. PROPOSED COMMERCIAL APPLICATIONS. There are excellent commercial prospects for computer software that allows the patient to rate their level of dyspnea associated with activities of daily living. Once the software package is implemented and tested, site licenses for acquiring the program will be sold to clinics, hospitals, and pharmaceutical companies worldwide. The computer assessment instruments developed in this project will quantify the patient-reported outcomes of lung disease. The overall goal is to further our understanding about these diseases and to identify better clinical outcome measures. [unreadable] [unreadable] [unreadable]